This invention relates generally to signal-pickup cartridges into be loaded to signal-pickup devices proper of apparatuses for reproducing signals recorded on rotary recording mediums. More particularly, the invention relates to a signal-pickup cartridge which is capable of positively protecting a reproducing stylus and other parts and is easily and conveniently handled.
A rotary recording medium (hereinafter referred to as a "disc") on which an information signal such as a video signal or an audio signal has been recorded as variations of geometrical shape has been reduced into practice. Also known and being reduced to practice are apparatuses of the type which reproduce from such a disc the thus recorded information in response to variations in the electrostatic capacitance between the disc and the electrode of a reproducing stylus. The signal pickup device used in a reproducing apparatus of this character consists essentially of a signal-pickup device proper comprising a tracking control means provided on the reproducing apparatus, a cartridge loading mechanism, and a signal-pickup cartridge having a reproducing stylus and related parts and loaded from the outside into the cartridge loading mechanism of the pickup device proper.
The assignee of the present application is also the assignee of a previous U.S. patent application Ser. No. 254,055, entitled "Signal pickup device in a rotary recording medium reproducing apparatus". In the specification of this previous application, there is disclosed a signal-pickup cartridge comprising a cartridge case supporting therewithin a cantilever having at its extreme end a reproducing stylus and a rotary lid of openable and closable character which is normally closed to cover the reproducing stylus and is opened at the time of loading. In this pickup cartridge, the rotary lid covers only the reproducing stylus and the extreme end side of the cantilever, and the proximal side of the cantilever is exposed to the outside. For this reason, there has been the problem of the risk of damage to the cantilever during handling and at the time of loading. Furthermore, this pickup cartridge is accompanied by another problem in that it is necessary to rotate the lid in the opening direction at the time of loading, and this means that the loading operation is that much more troublesome.